MicroRNA 98-5p Overexpression Contributes to Delayed Fracture Healing via Targeting BMP-2.

MicroRNAs (miRNAs) are related to the regulation of bone metabolism. Delayed fracture healing (DFH) is a common complication after fracture surgery. The study attempted to examine the role of miR-98-5p and bone morphogenetic protein (BMP)-2 with the onset of DFH. A total of 140 patients with femoral neck fracture were recruited, including 80 cases with normal fracture healing (NFH) and 60 cases with DFH. MC3T3-E1 cells were induced cell differentiation for cell function experiments. Real-time quantitative polymerase chain reaction (RT-qPCR) was carried out to test mRNA levels. Cell proliferation and apoptosis were determined via CCK-8 and flow cytometry assay. Luciferase reporter assay was done to verify the targeted regulatory relationship of miR-98-5p with BMP-2. In comparison with NFH cases, DFH patients owned high levels of serum miR-98-5p and low concentration of BMP-2, and the levels of the two indexes are significantly negatively correlated. Both miR-98-5p and BMP-2 had the ability to predict DFH, while their combined diagnostic value is the highest. BMP-2 was demonstrated to be the target gene of miR-98-5p. Overexpression of BMP-2 reversed the role of miR-98-5p in MC3T3-E1 cell proliferation, apoptosis and differentiation. Increased miR-98-5p and decreased BMP-2 serve as potential biomarkers for the diagnosis of DFH. MiR-98-5p overexpression inhibits osteoblast proliferation and differentiation via targeting BMP-2.

[Exploring the mechanisms of ferroptosis in non-obstructive azoospermia based on bioinformatics and machine learning].

OBJECTIVE: To explor the potential mechanisms of ferroptosis involvement in non-obstructive azoospermia based on bioinformatics and machine learning methods. METHODS: To obtain disease-related datasets and ferroptosis-related genes, we utilized the GEO database and FerrDb database, respectively. Using the R software, the disease dataset was subjected to normalization, differential analysis, and GO and KEGG enrichment analysis. The differentially expressed genes from the disease dataset were then intersected with the ferroptosis-related genes to identify common genes. Core genes were selected using three machine learning algorithms, namely LASSO, SVM-RFE, and random forest. Further analysis included exploring immune infiltration correlation, predicting target drugs, and conducting molecular docking simulations. RESULTS: The differential analysis of the GSE45885 dataset yielded 1751 differentially expressed genes, while the GSE145467 dataset yielded 4358 differentially expressed genes. The intersection of these two gene sets resulted in a disease-related gene set consisting of 508 genes. Taking the intersection of the disease-related gene set and the ferroptosis-related gene set, we obtained 17 disease-related ferroptosis genes. After machine learning-based screening, three core genes were identified: GPX4, HSF1, and KLHDC3. CONCLUSION: The mechanism underlying the involvement of ferroptosis in non-obstructive azoospermia may be linked to the downregulation of GPX4, HSF1, and KLHDC3 expression. This finding provides a basis for subsequent in-depth mechanistic and therapeutic studies.

[Simulated processing with vinegar changes chemical structures of main terpenoids in Euphorbiae Ebracteolatae Radix].

This study aims to explore the chemical structure transformation mechanisms of the main terpenoids in the effective fraction of Euphorbiae Ebracteolatae Radix(EER) during the processing with vinegar. The terpenoids including ent-11α-hydroxyabicta-8(14),13(15)-dien-16,12-olide(HAO), jolkinolide B(JNB), fischeria A(FA), and eupractenoid A(EA) were heated at 160 ℃ with 6% acetic acid for 40 min, and then LC-MS/MS was employed to analyze the structural transformation rules of the terpenoids. Further, we analyzed the changes in the relative content of the four compounds and their transformation products in raw and vinegar processed EER to verify the transformation rules during the simulated processing with vinegar. In addition, JNB and FA were processed with single heating, heating with water or heating with acetic acid. We then employed HPLC to compare the content of these two terpenoids and their transformation products before and after processing, so as to investigate the effect of different processing methods on chemical structure transformation. The results showed that the lactone ring of the abietane-type diterpenoids HAO and JNB and the norditerpene lactone FA were opened by heating with acetic acid. When there were hydroxyl groups in the structures, terpenoids were esterized to esters and oxidized to form carbonyl groups. When there was epoxy ring in the structures, ring opening reaction was easy to occur. During the heating with acetic acid, the heterodimeric diterpenoid EA underwent the cleavage of ether bond to produce the rosane-type diterpenoid euphebracteolatin A(EHTA) and another abietane-type diterpenoid. The changes in the relative content of terpenoids and their transformation products in raw and vinegar-processed EER were basically consistent with those of simulated processing of components with vinegar. The HPLC results revealed that the effect of different simulated processing methods on structural transformation varied. Heating with acid can change JNB and FA into new components. Heating with water can also promote the structural transformation, with the efficiency obviously lower than that of heating with acid. Direct heating had no influence on the structure of JNB, while it significantly reduced the relative content of FA. The components treated with direct heating did not produce the products like those of the heating with acid. These results indicated that vinegar plays a key role in the structural transformation of diterpenoids during the processing of EER with vinegar. The structural transformation of diterpenoids in EER during the processing with vinegar may be the material basis for vinegar processed EER to reduce toxicity and preserve effect.

[Effect of different parts of Pinelliae Rhizoma Decoction against airway inflammation and analysis of effective components].

This study investigated the material basis and mechanism of Pinelliae Rhizoma Decoction in the treatment of airway inflammation. The cigarette smoke combined with lipopolysaccharide(LPS) was used to induce an airway inflammation model in mice. The expression levels of IL-6 and IL-8 in the bronchoalveolar lavage fluid(BALF) and the phosphorylation levels of p38 and IκB in the lungs of mice were taken as indexes to screen the effective extracts by system solvent extraction from Pinelliae Rhizoma Decoction(dichloromethane extract, ethyl acetate extract, n-butanol extract, etc.). Meanwhile, the human bronchial epithelial(16-HBE) cell model of cigarette smoke extract(CSE)-induced injury was established, and the mRNA expression levels of IL-6 and IL-8 and the phosphorylation levels of p38 and IκB proteins were also taken as indexes to evaluate the anti-inflammatory effect of different extracts of Pinelliae Rhizoma Decoction. The results showed that Pinelliae Rhizoma Decoction significantly antagonized airway inflammation in mice by down-regulating the expression levels of IL-6 and IL-8 in mice with airway inflammation and 16-HBE cells with CSE-induced injury and inhibiting the phosphorylation levels of p38 and IκB. The dichloromethane and ethyl acetate extracts of Pinelliae Rhizoma Decoction showed significant anti-inflammatory effects, while such effects of other extracts were not prominent. Furthermore, the database of Pinelliae Rhizoma composition was constructed, and the components in effective extracts were analyzed by HPLC-TOF-MS and Nano-LC-MS/MS. As revealed by the results, the compositions of the two effective extracts were similar with 36 common components. They were combined and then divided into Pinelliae Rhizoma alkaloids(PTAs) and Pinelliae Rhizoma non-alkaloids(PTNAs) by 732 cation-exchange resin. Further in vitro investigation confirmed the significant anti-inflammatory effect of PTNAs, while such effect of PTAs was not manifest. The MS analysis showed 172 peptides and 7 organic acids in PTNAs. The peptide content in PTNAs was 63.5% measured by quantitative analysis of BCA assay, and the organic acid content was 9.92% by potentiometric titration method. The findings of this study suggested that Pinelliae Rhizoma Decoction could antagonize airway inflammation in mice by inhibiting phosphorylation of p38 and IκB and blocking the activation of MAPK and NF-κB signaling pathways, and the effective components were related to the peptides and organic acids in PTNAs. The above results lay a foundation for the research on the mechanism and material basis of Pinelliae Rhizoma in antagonizing airway inflammation.

[Effect of Pinelliae Rhizoma processed with lime and licorice on toxic lectin protein].

The present study was aimed to investigate the effect of lime and licorice processing of Pinelliae Rhizoma on its toxic lectin protein and clarify the scientific detoxification connotation of lime and licorice processing of Pinelliae Rhizoma. Western blot was used to semi-quantitatively analyze the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum. Raw products and lectin were treated by soaking in licorice juice, lime solution or mixture solution of these two to investigate the different processing time on the content of toxic lectin protein. SDS-PAGE gel electrophoresis was used to analyze the changes of lectin protein bands in the solution and precipitates before and after processing. MALDI-TOF technology was used to qualitatively analyze and compare the protein molecular weight before and after processing. The results showed that the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum were 5.01% and 0.04% respectively, indicating that processing could significantly reduce the content of active lectin in raw products. The results also showed that the content of lectin in raw drugs decreased significantly after soaking in lime solution for one day or in licorice juice for three day, and the effect was greatest in mixture solution. Qualitative analysis showed that after being treated by soaking in lime solution, the lectin protein was decomposed into small peptide segments, while after being treated by soaking in licorice juice, the lectin protein was denatured and precipitated. The structure of lectin protein in Pinelliae Rhizoma was broken after being processed with licorice juice and lime solution, which significantly reduced the content of toxic lectinprotein. This is one of the detoxification mechanisms of Pinelliae Rhizoma processing.

[Effect of processing on toxic components lectin from four kinds of Araceae toxic medicines].

The study aimed to investigate the effect of processing on lectin protein in four toxic Chinese medicines tubers of Pinellia ternata,P. pedatisecta,Arisema heterophyllum and Typhonium giganteum. Western blot was used to semi-quantitatively analyze the content of lectin in the four kinds of toxic Chinese medicines and their different processed products. Raw products and lectin were treated by heating or soaking in ginger juice or alum solution. The effects of different excipients and the heating methods on lectin proteins were investigated. The results showed that the content of lectin in raw products of P. pedatisecta,P. ternata,A. heterophyllum,and T. giganteum were 7. 3%,4. 9%,2. 7%,2. 3%,respectively. And the content of lectin in Pinelliae Rhizoma praeparatum cum alumine was 0. 027%. Lectin was not detected in the Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine,Arisaematis Rhizma Praeparatum and Typhonii Rhizoma Praeparatum,which indicated that processing could significantly reduce the content of active lectin in raw products. The results also showed that with the prolongation of soaking and heating time,the content of lectin in raw products decreased gradually,while the content was almost unchanged when soaked in ginger juice alone. The effects of different excipients and heating on lectin were the same as those on raw products. Therefore,the method with alum soaking and heating can reduce the content of active lectin,which is the key to reduce the toxicity of toxic Chinese medicines. In this paper,Western blot was used to study the content of toxic protein in Araceae toxic Chinese medicines as an evaluation method of the processing degree.

[Effects of toxic fractions of Euphorbiae Ebracteolatae Radix on toxicity of mice intestinal tract and colon aquaporins expression level before and after vinegar processing].

To investigate the toxicity changes of Euphorbiae Ebracteolatae Radix (EER) before and after vinegar processing, toxic diterpenoids were concentrated with chloroform as extraction solvent from EER. Then the residue was extracted for non-chloroform extract with 95% ethanol and water after extraction with chloroform. The chloroform extraction of vinegar processed EER was prepared with the same method. The mice received the drug by oral administration. Moisture content in mice feces, duodenum and colon tissue, aquaporin AQP1, AQP3, AQP4 protein expression levels were assayed as the indexes to investigate the toxicity variation of chloroform fraction, non-chloroform fraction, as well as intestinal tract toxicity before and after vinegar processing of EER. The results showed that the chloroform fraction extracted from EER could significantly increase the moisture content in mice feces, duodenum and colon, and decrease AQP1 protein expression level, increase AQP3 and AQP4 protein expression levels in the colon. The intestinal toxicity of the chloroform extract was significantly higher than that of non-chloroform extract. The moisture content in mice feces, duodenum and colon was significantly decreased, and the AQPs protein expression tended to be normal in the colon after vinegar processing. The results showed that the chloroform fraction extracted from EER could lead to diarrhea, intestinal edema, and the intestinal toxicity action was associated with interfering AQPs protein expression and promoting intestinal fluid transport disorder in mice. Vinegar-processing could reduce intestinal toxicity of EER, so vinegar processing was considered to be the scientific processing method of EER.

[Intestinal toxicity of different processed products of Crotonis Fructus and effect of processing on fatty oil and total protein].

To study the effect of different processes of Crotonis Fructus on fatty oil, total protein and intestinal toxicity, three kinds of processed products (heat Crotonis Semen Pulveratum, non-heat Crotonis Semen Pulveratum and diluted Crotonis Semen Pulveratum) were prepared. Mice were orally given Crotonis Fructus. The content of DAO and D-lactic acid in the serum were measured by ELISA to investigate the change of intestinal permeability in mice. Western blot was used to determine the expressions of tight junction proteins (occludin, claudin-1) in different intestinal tract, so as to observe the effect of Crotonis Fructus and its processed products on intestinal epithelial barrier. These results showed that Crotonis Fructus could significantly increase the intestinal permeability and reduce the expression of tight junction proteins in duodenum and jejunum, but with little impact on the ileum and colon. The intestinal permeability and the expression of tight junction proteins became normal after processing. However, the order of the toxicity of Crotonis Semen Pulveratum from high to low was non-heat Crotonis Semen Pulveratum > diluted Crotonis Semen Pulveratum≈4heat Crotonis Semen Pulveratum. According to the results of composition, the composition of fatty oil did not change during the processing, but the content and composition of total protein in Crotonis Semen Pulveratum changed significantly. The order of total protein content from high to low was that non-heat Crotonis Semen Pulveratum > heat Crotonis Semen Pulveratum > diluted Crotonis Semen Pulveratum. The molecular weight distribution of the total protein bands of non-heat Crotonis Semen Pulveratum and diluted Crotonis Semen Pulveratum was consistent, but the composition of total protein of heat Crotonis Semen Pulveratum significantly changed as evidenced by decreased and thin some stripes. This indicated that heating and dilution could reduce the content of total protein, and heating could cause partial protein denaturation and inactivation. In conclusion, both dilution and heating can reduce the toxicity of Crotonis Fructus, but the heating shows a more significant attenuation effect, indicating that heating is the key step in Crotonis Semen Pulveratum preparation.

A study on molecular mechanism of Xihuang pill in the treatment of glioblastoma based on network pharmacology and validation in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Xihuang pill has been utilized to treat cancer for more than three hundred years in China. The molecular mechanisms of Xihuang pill in treating glioblastoma remains unclear. AIM OF THE STUDY: This study aimed to explore the core molecular mechanisms of Xihuang pill in treating glioblastoma by an integrative pharmacology-based investigation. MATERIALS AND METHODS: The main active compounds of Xihuang pill were identified from TCMSP, BATMAN-TCM, TCMID and CNKI. Glioblastoma-related therapeutic targets were retrieved from GeneCards and UniProt. Subsequently, a protein-protein interaction (PPI) network analysis was constructed using STRING. GO and KEGG enrichment were performed to analyze the intersection targets between the active compounds of Xihuang pill and glioblastoma. Based on the above analysis, we built a CTP network. The in vitro and in vivo experiments were further performed to validate the crucial molecular targets of Xihuang pill for the treatment of glioblastoma. RESULTS: A total of sixty active compounds of Xihuang pill and ten potential targets related to glioblastoma were found. Based on topological analysis, fourteen ingredients were selected as the main active compounds, and MY11 might be the most important metabolite in Xihuang pill. PI3K/Akt signaling pathway and receptor tyrosine kinases were considered as crucial targets for Xihuang pill against glioblastoma through KEGG enrichment and CTP analysis. The present experiments indicated that Xihuang pill suppressed the activation of PI3K/Akt/mTOR signaling pathway in glioblastoma cells and mouse xenografts via modulating the expression of PTEN and Rheb proteins, the interaction between TSC2 and Rheb, and the production of PIP3. Meanwhile, after glioblastoma cells treatment with Xihuang pil, the release of IL-1ß, INF-γ was increased and the production of IL-10, TGF-ß1 was decreased in glioblastoma cells after incubated with Xihuang pill. In addition, the activation of the upstream positive modulators of PI3K/Akt/mTOR pathway including PDGF/PDGFR and FGF/FGFR signaling were down-regulated in glioblastoma cells and mouse xenografts after treatment with Xihuang pill. CONCLUSION: Taken together, Xihuang pill inhibiting glioblastoma cell growth might be partly through down-regulating the activation of PDGF/PDGFR or FGF/FGFR-PI3K/Akt/mTOR signaling axis and improving immuno-suppressive micro-environment of glioblastoma.

Association between the nucleosome footprint of plasma DNA and neoadjuvant chemotherapy response for breast cancer.

Gene expression signatures have been used to predict the outcome of chemotherapy for breast cancer. The nucleosome footprint of cell-free DNA (cfDNA) carries gene expression information of the original tissues and thus may be used to predict the response to chemotherapy. Here we carried out the nucleosome positioning on cfDNA from 85 breast cancer patients and 85 healthy individuals and two cancer cell lines T-47D and MDA-MB-231 using low-coverage whole-genome sequencing (LCWGS) method. The patients showed distinct nucleosome footprints at Transcription Start Sites (TSSs) compared with normal donors. In order to identify the footprints of cfDNA corresponding with the responses to neoadjuvant chemotherapy in patients, we mapped on nucleosome positions on cfDNA of patients with different responses: responders (pretreatment, n = 28; post-1 cycle, post-3/4 cycles, and post-8 cycles of treatment, n = 12) and nonresponders (pretreatment, n = 10; post-1 cycle, post-3/4 cycles, and post-8 cycles of treatment, n = 10). The coverage depth near TSSs in plasma cfDNA differed significantly between responders and nonresponders at pretreatment, and also after neoadjuvant chemotherapy treatment cycles. We identified 232 TSSs with differential footprints at pretreatment and 321 after treatment and found enrichment in Gene Ontology terms such as cell growth inhibition, tumor suppressor, necrotic cell death, acute inflammatory response, T cell receptor signaling pathway, and positive regulation of vascular endothelial growth factor production. These results suggest that cfDNA nucleosome footprints may be used to predict the efficacy of neoadjuvant chemotherapy for breast cancer patients and thus may provide help in decision making for individual patients.

Low-Coverage Sequencing of Urine Sediment DNA for Detection of Copy Number Aberrations in Bladder Cancer.

PURPOSE: Chromosomal copy number aberrations (CNAs) are a hallmark of bladder cancer and a useful target for diagnostic explorations. Here we constructed a low-coverage whole-genome sequencing method for the detection of CNAs in urine sediment DNA from patients with bladder cancer. PATIENTS AND METHODS: We conducted a prospective study using urine sediment samples from 65 patients with bladder tumors, including 54 patients with bladder cancer and 11 patients with benign bladder tumors. Forty-three healthy individuals were included as normal controls. DNA was extracted from urine sediments and analyzed by low-coverage whole-genome sequencing to compare differences in CNAs among these three groups. CNAs are defined by arbitrary R values (normal range ± 2). When these values exceed ± 0.2 of normal range, gain/duplication or loss/deletion are suspected. RESULTS: With this method, CNAs were detected in 39 of 51 patients with bladder cancer, 2 of 10 patients with benign bladder tumors, and 8 of 39 normal controls. The lengths of DNA deletion and duplication were significantly larger in patients with bladder cancer than in patients with benign tumors or normal controls (P < 0.05). Bladder cancer duplicate CNAs mainly occurred on chromosomes 1q, 5p, 6p, 7p, 8q, and 13q, while deletions mainly occurred on 2q, 8p, 9q, 9p, and 11p. Those regions contained bladder cancer tumor-related genes, such as STK3, COX6C, SPAG1, CDKAL1, C9orf53, CDKN2A, CDKN2B, MIR31, and IFNA1. The number of CNAs detected in urine sediment DNA during the follow-up period was significantly reduced. CONCLUSION: Our sequencing method is highly sensitive and can detect a minimal chromosome repeat/microdeletion change of 0.15 Mb. The use of 0.1~0.3× low-coverage whole-genome sequencing can be used to detect bladder cancer CNAs in urine sediment DNA. This method provides a promising method for noninvasive diagnosis of bladder cancer, but still needs further verification in a larger sample size.

Growth and wood/bark properties of Abies faxoniana seedlings as affected by elevated CO2.

Growth and wood and bark properties of Abies faxoniana seedlings after one year's exposure to elevated CO2 concentration (ambient + 350 (+/- 25) micromol/mol) under two planting densities (28 or 84 plants/m(2)) were investigated in closed-top chambers. Tree height, stem diameter and cross-sectional area, and total biomass were enhanced under elevated CO2 concentration, and reduced under high planting density. Most traits of stem bark were improved under elevated CO2 concentration and reduced under high planting density. Stem wood production was significantly increased in volume under elevated CO2 concentration under both densities, and the stem wood density decreased under elevated CO2 concentration and increased under high planting density. These results suggest that the response of stem wood and bark to elevated CO2 concentration is density dependent. This may be of great importance in a future CO2 enriched world in natural forests where plant density varies considerably. The results also show that the bark/wood ratio in diameter, stem cross-sectional area and dry weight are not proportionally affected by elevated CO2 concentration under the two contrasting planting densities. This indicates that the response magnitude of stem bark and stem wood to elevated CO2 concentration are different but their response directions are the same.

Alleviation of drought stress in Phyllostachys edulis by N and P application.

The aim of this study was to explore whether nutrition supply can improve the drought tolerance of Moso bamboo under dry conditions. One-year-old seedlings were exposed to two soil water content levels [wellwatered, 70 ± 5% soil-relative-water-content (SRWC) and drought stress, 30 ± 5% SRWC] and four combinations of nitrogen (N) and phosphorus (P) supply (low-N, low-P, LNLP; low-N, high-P, LNHP; high-N, high-P, HNHP; and high-N, low-P, HNLP) for four months. Plant growth, photosynthesis, chlorophyll fluorescence, water use efficiency and cell membrane stability were determined. The results showed that drought stress significantly decreased total biomass, net-photosynthesis (Pn), stomatal-conductance (gs), leaf-chlorophyll-content (Chlleaf), PSII-quantum-yield (ΦPSII), maximum-quantum-yield-of-photosynthesis (Fv/Fm), photochemical-quenching-coefficient (qP), leaf-instantaneous-water-use efficiency (WUEi), relative-water-content (RWC), photosynthetic-N-use-efficiency (PNUE), and photosynthetic-P-use-efficiency (PPUE). N and P application was found to be effective in enhancing the concentration of leaf N, gs, and Pn while reducing the production of reactive oxygen species under both water regimes. Under LNHP, HNHP and HNLP treatments, the decreases in total biomass, Pn, Chlleaf and Fv/Fm of drought-stressed were less evident than the decreases under LNLP. The study suggests that nutrient application has the potential to mitigate the drastic effects of water stress on Moso bamboo by improving photosynthetic rate, water-use efficiency, and increasing of membrane integrity.

Accumulated Spinal Axial Biomechanical Loading Induces Degeneration in Intervertebral Disc of Mice Lumbar Spine.

OBJECTIVE: To investigate the effect of accumulated spinal axial biomechanical loading on mice lumbar disc and the feasibility of applying this method to establish a mice intervertebral disc degeneration model using a custom-made hot plate cage. In previous studies, we observed that the motion pattern of mice was greatly similar to that of humans when they were standing and jumping on their lower limbs. There is little data to demonstrate whether or not accumulated spinal axial biomechanical loading could induce intervertebral disc degeneration in vivo. METHODS: Twenty-four 0-week-old mice were randomly divided into model 1-month and 3-month groups, and control 1-month and 3-month groups (n = 6 per group). The model groups was transferred into the custom-made hot plate cage three times per day for modeling. The control group was kept in a regular cage. The intervertebral disc samples of the L3 -L5 were harvested for histologic, molecular, and immunohistochemical studies after modeling for 1 and 3 months. RESULTS: Accumulated spinal axial biomechanical loading affects the histologic, molecular, and immunohistochemical changes of mice L3- L5 intervertebral discs. Decreased height of disc and endplate, fissures of annulus fibrosus, and ossification of cartilage endplate were found in morphological studies. Immunohistochemical studies of the protein level showed a similar expression of type II collagen at 1 month, but a slightly decreased expression at 3 months, and an increased expression level of type X collagen and matrix metalloproteinase 13 (MMP13). Molecular studies showed that ColIIa1 and aggrecan mRNA expression levels were slightly increased at 1 month (P > 0.05), but then decreased slightly (P > 0.05). ColXa1, ADAMTS-5, and MMP-13 expression levels werer increased both at 1 and 3 months (P < 0.05). In addition, increased expression of Runx2 was observed. CONCLUSION: Accumulated spinal axial loading provided by a custom-made hot plate accelerated mice lumbar disc and especially endplate degeneration. However, this method requires further development to establish a lumbar disc degeneration model.

[Effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of western Sichuan, China].

By using open-top chamber (OTC), the effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of Western Sichuan were studied. The results showed that comparing with the control, the mean air temperature at 1.2 m above the ground throughout S. eriostachya growth season in OTC increased by 2.9 degrees C, while the soil temperature at the depth of 5 cm only increased by 0.4 degrees C. The temperature increase in OTC made S. eriostachya budding advanced and defoliation postponed obviously, and the leaf life-span longer. The leaf and branch growth rates as well as the specific leaf area in OTC increased obviously, whereas the leaf nitrogen concentration decreased significantly. In OTC, the stomata conductance, net photosynthetic rate, photorespiration, and dark respiration rate of S. eriostachya all exhibited an increasing trend. It was suggested that S. eriostachya had stronger capability to adapt to warming, and, under the background of future global climate change, the elevation of S. eriostachya distribution in the timberline ecotone would be likely to ascend.

[Effects of forest canopy gap on Abies faxoniana seedling's biomass and its allocation in sub-alpine coniferous forest of West Sichuan].

By the method of strip transect sampling, the density, height, basal diameter, and components biomass of Abies faxoniana seedlings (H < or = 100 cm) lived in the forest gap (FG) and under the forest canopy (FC) of subalpine natural coniferous forest in West Sichuan were investigated, and the relationships among different components biomass were analyzed. The results indicated that the density and average height (H) of A. faxoniana seedlings were significantly different in FG and under FC, with the values being 12 903 and 2 017 per hectare, and 26.6 cm and 24.3 cm, respectively, while no significant differences were found in average basal diameter (D) and biomass. The biomass allocation in seedling's components was markedly affected by forest gap. In FG, the biomass ratio of branch to trunk (BRBT) reached the maximum (1.54) at 12th year, and then, declined and fluctuated at 0. 69. Under FC, the BRBT was increased with seedlings growth, and exceeded 1.0 at about 15th year. The total biomass and the biomass of leaf, stem, shoot and root grown in FG and under FC were significantly linearly correlated with D2H. There were significant positive correlations among the biomass of different seedling's components.